The present invention relates to a moving obstacle detecting device installed on a vehicle or other moving body and serving to detect the existence of a moving obstacle in the vicinity of the moving body.
An example of an existing device installed on a vehicle and serving to detect the existence of another vehicle or a pedestrian that will cross in front of the vehicle is disclosed in Japanese Laid-open Patent Publication No. Hei9-259282 (Patent Document 1). In Patent Document 1, an image captured by photographing the surroundings of the vehicle is divided into two regions, one in which a moving obstacle exists and one in which the obstacle does not exist, and the position and direction of movement of the obstacle is calculated based on output obtained from the two regions.
The method of identifying the moving obstacle during this processing is to divide the image into small regions and calculate an overall estimated residual value for each region. By using an overall estimated residual value, when the foci of expansion (FOE) of motion vectors of the optical flow are calculated, the regions in which a moving object exists can be determined by finding the regions where there are more than one foci of expansion, i.e., the regions where extension lines coinciding with the motion vectors of the optical flow do not converge into a single focus of expansion.